fix: use opacity in acrylic background

Author: std-microblock

src/ui/extra_widgets.cc

@@ -36,6 +36,7 @@ void acrylic_background_widget::render(nanovg_context ctx) {
   widget::render(ctx);
   cv.notify_all();
 
+  bg_color.a = *opacity / 255.f;
   ctx.fillColor(bg_color);
   ctx.fillRoundedRect(*x, *y, *width, *height, use_dwm ? 8.f : **radius);